1. Technical Field
The disclosure relates generally to an applicator for applying a tissue sealant based on human or animal proteins and more particularly to an apparatus for applying an adhesive formed by combining solutions of the proteins to tissues or organs for sealing wounds, stopping bleeding and the like.
2. Description of Related Art
A fibrin sealant is a biological adhesive formed by mixing two protein components, namely, fibrinogen and thrombin. Each protein component is derived from human plasma and is subjected to virus elimination procedures. The components are typically individually dehydrated and stored in separate vials as sterile freeze-dried powders.
It is known that purified fibrinogen and thrombin, together with a variety of known adjuvants, can be combined in vitro to produce a polymer having great potential benefit, both as a hemostatic agent and as a tissue adhesive. Because of the rapid polymerization upon intimate interaction of fibrinogen and thrombin, it is important to maintain these two blood proteins separate until applied at the application site. These protein solutions are generally delivered by devices such as a dual syringe apparatus.
One dual syringe apparatus for applying a fibrinogen-based tissue adhesive is disclosed in U.S. Pat. No. 4,359,049 to Redl et al. Redl et al. disclose a mechanism in which two standardized one-way syringes are held in a support having a common actuating means. The dispensing end of each syringe is inserted into a collection manifold where the two components are mixed. The components are then dispensed through a common needle capable of covering a limited area of the application site.
It is often desirable or necessary to cover a broad area of a wound, either to stop bleeding, to fix tissue or to prevent infection. It is also desirable to prevent the two components from mixing within the dispensing device.
Further, all known devices for dispensing solutions of fibrinogen and thrombin require the addition of these proteins in powdered form to the body of the syringe. This makes the proteins susceptible to contamination by impurities which may enter the syringe body. Further still, the use of the syringe body to mix the proteins with water to create the protein solutions can cause the solutions to leak out from either the dispensing end of each syringe or the proximal end of the syringe body.
Additionally, a dual syringe apparatus for the application of fibrinogen and thrombin solutions to an application site generally contains several parts, such as a syringe plunger, a xe2x80x9cYxe2x80x9d manifold connector, a dispensing needle, a syringe holder, syringe needles, and conduits for transporting the solutions to the dispensing needle. Therefore, known fibrin sealant applicators, such as disclosed in U.S. patent to Redl et al. discussed above, and in U.S. Pat. No. 4,874,368 to Miller et al. and U.S. Pat. No. 4,979,942 to Wolf et al. are difficult to reuse. The replenishment of the protein components typically require removing a clip which couples the syringe plunger, removing the syringe plunger, detaching the syringes from the xe2x80x9cYxe2x80x9d connector, removing the syringes from the holder, inserting new syringes, affixing the syringes to the xe2x80x9cYxe2x80x9d connector, adding fibrinogen to one syringe and thrombin to another syringe, adding sterile water to each syringe, replacing the syringe plunger, replacing the plunger clip, and mixing the solutions. In an application where time is of the essence, such a lengthy replenishing process is impractical and cumbersome.
Furthermore, known applicators for dispensing a biological adhesive require the manual exertion of a force on the protein components so they can be dispensed from the applicator. Typically, a manual force is exerted on the components by means of the plunger in the standard one-way syringe. This type of arrangement is shown in U.S. Pat. No. 4,359,049 discussed above, and U.S. Pat. No. 4,631,055 to Redl et al. Manually exerting a force on a plunger located at proximal end of the applicator can make the application of the adhesive difficult. For example, the user is unable to clearly view the application site when holding the applicator perpendicularly to the application site. Further, such an arrangement causes air to enter the syringes causing difficulty in exerting a force via the syringe plunger.
Thus, there is a need in the art for a fibrin sealant applicator wherein the adhesive covers a broad area of a wound, either to stop bleeding, to fix tissue or to prevent infection. There is also a need for a fibrin sealant applicator wherein a manual force is applied via an activator assembly having a mechanism for preventing air from entering reservoirs containing the solutions. Further, there is a need for a fibrin sealant applicator wherein the adhesive components are not susceptible to contamination and the adhesive components are not intermixed within the applicator.
In addition, there is a need for a fibrin sealant applicator wherein the component solutions are easily replenished. There is also a need for a fibrin sealant applicator which is self-cleaning and reusable with different component solutions. Further, there is a need for a fibrin sealant applicator which is inexpensive to manufacture for allowing the applicator to be disposed of after use. Additionally, there is a need for a fibrin sealant applicator which avoids wasting adhesive solution and allows the application site to be clearly seen by the user when applying the component solutions perpendicular to the application site.
An applicator is provided for dispensing a first and a second component of a biological adhesive. The applicator includes a housing having a housing head for enclosing therein a first reservoir containing the first component, and a second reservoir containing the second component. The housing further includes an elongated body portion defining a longitudinal axis for enclosing therein a conduit assembly having a first and a second conduit in communication with the first and second reservoir, respectively. An activator assembly is provided which includes an activator and a rachet mechanism for compressing the reservoirs within the housing to dispense the biological components into the conduits. An applicator tip having two separate channels in communication with the conduits may be provided on a distal end of the elongated body portion for dispensing the components at the application site. The first and second components are preferably fibrinogen and thrombin which intermix to form a fibrin sealant.